| Euphorbia lathyris L.is a plant with a very high content of fatty acids,especially oleic acid.It is an ideal raw material for biodiesel Production.The distribution of Euphorbia lathyris in our country is very extensive.There is a large area of cultivation in the south.The Euphorbia lathyris has strong resistance,high yield,easy to survive,and has low requirements for the growth environment.It has good development potential.Photosynthesis is the fundamental source and way to Product plant oils,which directly affects the level of plant yield and quality.The photosynthetic character of Euphorbia lathyris was investigated by taking random sampling methods.Considering the soil and climatic conditions in Shanxi,the physiological and ecological changes of the Euphorbia lathyris.under drought,low temperature,and salt stress were studied.Finally,the dynamic changes of fatty acid content of seed in six consecutive stages were measured by gas chromatography.The results show:1.The net photosynthetic rate exhibited a "double peak" phenomenon in the measurement of the accompanying solar radiation,and reached the peak of 13.62 μmol ·m-2·s-1 around 10:00,and it was between 11:00 and 14:00.There is a clear lunch break.Net photosynthetic rate was not significantly correlated with temperature,relative humidity,and relative CO2 concentration.It was significantly positively correlated with transpiration rate and stomatal conductance,and had a significant negative correlation with intercellular CO2 concentration.2.In the adversity stress test,the content of superoxide dismutase SOD increased first and then decreased.Proline Pro kept growing.MDA content had a slight increase,but the change is not obvious.With the increase of NaCl concentration,the activity of SOD increased first and then decreased;Pro content increased rapidly during moderate stress,reached the maximum value in severe stress and the content was more than nine times that of the CK;MDA content also maintained an upward trend.With the persistence of low temperature,SOD activity increased first and then decreased.Under severe stress,the content of SOD was lower than the CK;Pro content also maintained the trend of increasing first and then decreasing;MDA content continued to increase.This shows that drought resistance of Euphorbia lathyris is the strongest,while the cold resistance is the weakest.3.In the microscopic observation of the developing seed,it was found that as the development of seed,the color of the seed coat changed from green to light yellow and eventually became brown,the seed coat constantly hardened,and patterns and gutters appeared later.It becomes rougher;caruncle change from transparent to waxy yellow,the seeds change from transparent,semi-liquid to milky solid,the embryo gradually elongates,and it’s color of seed changes from transparent to milky white.4.The main fatty acids in Euphorbia lathyris include six kinds:palmitic,oleic,linoleic,linolenic,arachidonic and stearic acids.At different developmental stages,the relative content of fatty acids varies obviously.With the gradual development of continuous seeds,the relative content of oleic acid in seeds increased rapidly from 15 to 29 days after anthesis,accompanied by a decrease in the relative content of palmitic acid,linoleic acid,and arachidonic acid;During the period from 29 to 50 days.The contents of the six fatty acids tended to be stable,while the relative contents of stearic acid and linolenic acid did not change significantly during the entire development period.The correlation analysis showed that the content of oleic acid was significantly negatively correlated with the contents of palmitic acid,arachidonic acid,and linoleic acid.The results of the research of crude oil showed that the content of crude oil gradually increased with the development of the seed and reached a maximum at the 50th day after anthesis.The highest content was 39.02%.Therefore,the critical period of accumulation of oleic acid content is 15 to 29 days after flowering,and with the development of seeds,the content of saturated fatty acids keeps falling,and the content of unsaturated fatty acids keeps rising. |
